Valve silencers



July 8, 1958 G. M. BRAUN 2,842,111

VALVE SILENCERS Filed Nov. A115, 1956 N35 J0 al j INVENTOR 65ans: M. emw

United States Patent O VALVE SILENCERS George M. Braun, Milwaukee, Wis.Application November 13, 1956, Serial No. 621,939

(Cl. 12S-1821) My invention relates to improvements in valve silencers.

The object of my invention is to provide a valve silencer for poppetvalve actuation `such as is found in modern internal combustion enginesand other poppet valve equipped machinery.

My device is located between the end of the valve stem and the camfollower, and an important feature of my invention is the provision of asimple silencing spring device formed in one piece and so shaped as tobe positively located for its operation and to provide the simplest andmost trouble free element to take the impact of valve actuation.

In the drawings:

Fig. 1 is a vertical section through that fragmentary portion of aninternal combustion enginewhich shows a poppet valve and itsenvironment, my valve silencer being shown in position between thepoppet valve` and its spring, and the cam follower.

Fig. 2 is a top plan view of my valve silencer.

Fig. 3 is a side elevation of the silencer shown in Fig. 2.

I am aware that spring elements have heretofore been provided forlocation between a cam follower and the valve stem which the camfollower is intended to actuate. Such a silencer is shown in U. S.Patent No. 1,395,064 to C. D. Stromgren, October 25, 1921, but it willbe seen from the following description that my device is greatlysimplified and is much more effective for longer periods of time withoutservice requirement.

As shown in the drawings, the environment in which my silencer is usedincludes the usual cam follower mounted in a guide 11 carried by flange12 of cylinder 13 of an internal combustion engine, As shown somewhatdiagramrnatically, the lower end of the cam follower is provided with aroller 14 mounted in a roller bracket 15 secured to the lower end of thefollower 10. The roller 14 is thus positioned to be actuated by a cam 16in the well known manner as the cam follower is reciprocated upwardlyand downwardly in response to cam action. Valve is guided by valve guide21 in which valve stem 22 is mounted to reciprocate upwardly anddownwardly in response to cam follower reciprocation. At the lower endof the valve stem 22 is a key 23 which may be made in any one of themany acceptable shapes, but which is usually horseshoe shaped andreceivable into a groove in the stem so as to provide a stop againstwhich a somewhat cup shaped spring seat 24 may rest under the bias ofvalve spring 25. This spring 25 is a compression spring bearing at itslower end against the cup shaped spring scat 24 and at its upper endagainst the lower surface 26 of what is, in this particularlydisclosure, an L head engine. Thus the valve stem 22 is constantly urgedto its lower position whereby to rrnly seat the valve 20 against a valveseat 27 which surrounds a port 28.

As is customary in valve actuating mechanisms of this general type, thecam follower 10 is provided with an axially aligned adjusting screw 30,which is usually in the form of a cap screw, in threaded engagement withthe cam follower 10 and the usual lock nut at 31 is provided.Conventonally, the top of the cap screw 30 is in position to bear uponthe unprotected valve stem 22 2 Claims.

Z,842,1 11 Patented July 8, 1958 ICS and as is customary in theadjustment of these valves some clearance is provided between the top ofthe cap screw and the end of the stem to permit of some tolerance forexpansion and contraction of the metals during heating and cooling ofthe engine.

It is into the environment above described and particularly between thecap screw 30 at the end of the cam follower 10 and beneath the cuppedspring seat washer 24 i that my valve silencing device 35 is installed.My device 35 is made of a sheet or strip of spring metal. I shape thisin a folding operation so that my silencer includes a lower plate 36 andan upper plate 37 joined by a somewhat cylindrical spring margin 38. Thelower plate 36 is imperforate and the upper plate 37 is providedapproximately centrally with an aperture 39 through which valve stem 22is snugly receivable.

The area of the upper plate 37 is sufficient so that the spring seatwasher 24 may bear liatly against it when my device is in workingposition as shown in Fig. 1. When my silencer is removed from itsworking position, it takes the position shown in Fig. 3.

The strength of the spring action provided by the device 35 is ample toforce cam follower 10 downwardly upon the cam 16 throughout the entireworking cycle of Cam 16 at all speeds of the engine, but, of course, the

' strength of the spring action of my device is nowhere near adequate tocompress valve spring 25. It is merely a booster for the return of camfollower 10 in this respect.

It will be noted that when in working position, my device is so disposedthat the valve stem extends through aperture 39 and closely approximatescontact with the upper surface of plate 36; therefore, there is nomaterial other than plate 36 between the top of the cap screw 30 and thelower surface at the end of valve stem 22.

It will thus be apparent that my valve silencer is of the greatestsimplicity of construction, that it cannot be accidentally mislocatedwith respect to its work environment and it in no sense complicates theadjustment of cap screw 30 and the clearance relationship which must bemaintained in the valve action. The clearance is deiinitely providedbetween the valve stem and the upper surface of plate 36.

l claim:

1. A device of the character described. comprising a hat sheet area ofspring material shaped intermediately to provide a partially cylindricalspring fold and having areas either side of the fold divergent `fromeach other when in spring relaxed position, one of said areas beingapertured centrally, the other of said areas opposite said aperturebeing imperforate.

2. A device of the character described for interposition between a camfollower assembly and a valve stem having a cupped spring securedadjacent the end of the valve spring, said silencer comprising animperforate plate to bear in at contact against the cam followerassembly, integral semi-cylindrical spring margin for said imperforateplate and connected integrally with an upper platc centrally aperturedfor snug reception of the end of the valve stem and sufficient area toprovide full abutment against said spring seat.

References Cited in the file of this patent UNITED STATES PATENTS399,447 Stiles Mar. l2, 1889 1,613,117 Miller lan. 4, 1927 1,893,098Murray et al. Ian. 3, 1933 1,913,241 Kuse -n June 6, 1933 2,046,087Pountnay lune 30, 1936 2,643,069 Carlin lune 23, 1953 2,707,092 BowditchApr. 26, 1955

